The invention relates to an automated transmission comprising a hydraulic control device and comprising one or more hydraulic drive units. Furthermore, the invention relates to a method for operating an automated transmission, wherein by a base pressure control valve, a hydraulic pressure for a hydraulic control device is controlled, and by suitable pressure control valves actuating pressures for actuating the gear units are controlled.
From the published patent application EP 1 635 091 A1 an automated transmission in the form of a dual clutch transmission is known, comprising a first clutch for a first gear train, a second clutch for a second gear train, and a switching system for engaging and disengaging gears in the two partial transmission of the dual clutch transmission, wherein the clutches and the switching system represent the hydraulically actuated gear units. The hydraulic control device of the dual clutch transmission comprises a control unit with control valves for actuating the two clutches and the switching system, the hydraulic control device providing a controllable pressure and/or an adjustable volume flow for the clutches and/or for the switching system. In addition, the hydraulic control device has a switching device that is arranged between the control unit and the clutches or between the control unit and the switching system, the switching device allowing to switch the respective variable pressure or volume flow to the clutches or to the switching system. Although this hydraulic control device is a good compromise between functionality and design complexity, there is a permanent desire to further decrease the design complexity and therefore to provide control devices and dual clutch transmissions at lower costs.
Providing the base pressure and the actuating pressures for clutches and shift system requires energy and therefore reduces the efficiency of the dual clutch transmission.